Making a good cup of espresso is often considered an art form. Traditionally, the best espresso is made by a barista, a person highly skilled in controlling the variables that result in a finely brewed cup of espresso. These variables include brew water temperature and pressure, coffee weight, age, moisture, particle size, tamp pressure, etc. These variables contribute to the resistance that the coffee creates and allows the water to perform the required brewing work.
The barista generally uses an adjustable burr grinder to grind a dose of coffee. The particle sizes that the burr grinder produces, however, may be widely variable. A variable particle size distribution may cause the coffee to have an off taste. For example, a grind with too many large particles may be under brewed while a grind with too many small particles may be over brewed. Particularly, the use of the smaller particles may provide an undesirable level of bitterness.
There is a desire, therefore, for methods and devices that provide a desired particle size distribution on a consistent basis. Preferably, the methods and devices should be adaptable to providing grinds with any desired particle size distribution.